Department of Biology, University of Iowa, 163 Jefferson Street, Iowa City, IA 52242, USA.
Peptides. 2010 Mar;31(3):402-7. doi: 10.1016/j.peptides.2009.09.026. Epub 2009 Sep 28.
The allatostatins (ASTs) with Phe-Gly-Leu-amide C-terminal sequence are multifunctional neuropeptides discovered as inhibitors of juvenile hormone (JH) synthesis by corpora allata (CA) of cockroaches. Although these ASTs inhibit JH synthesis only in cockroaches, crickets, termites and locusts, isolation of peptides or of cDNA/genomic DNA or analysis of genomes indicates their occurrence in many orders of insects with the exception of coleopterans. The gene for these ASTs has not been found in the genome of the red flour beetle Tribolium castaneum (Family Tenebrionidae). Yet, in view of widespread occurrence of these peptides in insects, crustaceans and nematodes, they would be expected to occur in beetles. This study provides evidence for the presence of FGLa-like ASTs in the tenebrionid beetle, Tenebrio molitor, and scarabid beetle, Popillia japonica. Extract of brain from both beetles inhibited JH synthesis by cockroach CA dose dependently and reversibly. 20 brain equivalents of T. molitor and P. japonica extracts inhibited JH synthesis 64+/-5 and 65+/-0.6% respectively. Antibody against cockroach allatostatin (Diploptera punctata AST-7) used in an enzyme-linked immunosorbent assay reacted with brain extract of these beetles. Antibody against D. punctata AST-5 localized FGLa-like ASTs in the brain and subesophageal ganglion of T. molitor and P. japonica. In addition, pretreatment of T. molitor brain extract with anti-D. punctata AST-5 reduced the inhibition of JH synthesis and pretreatment of anti-D. punctata AST-5 with D. punctata AST-5 diminished the immunoreactivity of the antibody. Thus we predict that FGLa-like allatostatins will be found in beetles.
具有 Phe-Gly-Leu-amide C 末端序列的 Allatostatins (ASTs) 是多功能神经肽，最初被发现为蟑螂的咽侧体（CA）抑制保幼激素（JH）合成的抑制剂。尽管这些 ASTs 仅在蟑螂、蟋蟀、白蚁和蝗虫中抑制 JH 合成，但肽或 cDNA/基因组 DNA 的分离或基因组分析表明，除了鞘翅目昆虫外，它们存在于许多昆虫目中。这些 ASTs 的基因尚未在赤拟谷盗（拟谷盗科）的基因组中发现。然而，鉴于这些肽在昆虫、甲壳类动物和线虫中广泛存在，预计它们也会存在于甲虫中。本研究提供了 Tenebrionid 甲虫黄粉虫（Tenebrio molitor）和金龟子科甲虫日本金龟（Popillia japonica）中存在 FGLa 样 ASTs 的证据。这两种甲虫脑提取物均剂量依赖性地可逆抑制蟑螂 CA 的 JH 合成。20 个脑当量的 T. molitor 和 P. japonica 提取物分别抑制 JH 合成 64+/-5%和 65+/-0.6%。在酶联免疫吸附测定中使用的针对蟑螂 Allatostatin（Diploptera punctata AST-7）的抗体与这些甲虫的脑提取物反应。针对 D. punctata AST-5 的抗体将 FGLa 样 ASTs 定位在 T. molitor 和 P. japonica 的脑中及食管下神经节。此外，用抗 D. punctata AST-5 预处理 T. molitor 脑提取物可降低 JH 合成的抑制作用，而用 D. punctata AST-5 预处理抗 D. punctata AST-5 可降低抗体的免疫反应性。因此，我们预测在甲虫中会发现 FGLa 样 Allatostatins。
